Enhanced phase segregation induced by dipolar interactions in polymer blends

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Macromolecules

OSTI ID:1157120

Kumar, Rajeev ^[1]; Muthukumar, Murugappan ^[2]; Sumpter, Bobby G ^[1]

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1. ORNL
2. University of Massachusetts, Amherst

We present a generalized theory for studying phase separation in polymer blends containing dipoles on their backbone. The theory is used to construct co-existence curves and study the effects of dipolar interactions on interfacial tension for a planar interface between the coexisting phases. It is shown that mismatch in monomeric dipole moments leads to destabilization of homogeneous phase. Corrections to the Flory-Huggins phase diagram are predicted using the theory. Furthermore, it is found that interfacial tension increases with an increase in the mismatch. Density profiles and interfacial tensions are constructed for diffuse and sharp polymer-polymer interfaces by extending Cahn-Hilliard and Helfand-Tagami-Sapse s treatment, respectively. Correlating dipole moments with the dielectric constant of pure phases, it is demonstrated that effects of mismatch between the dipole moments of the two monomers is equivalent to the dielectric mismatch between the polymers.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1157120
• Journal Information: Macromolecules, Vol. TBD
• Country of Publication: United States
• Language: English